Children suffering from mild anxiety are likely to be better off if in school, as more time off might only make their symptoms worse, headteachers have been told.

In a letter to schools addressing issues surrounding attendance, England’s chief medical officer Chris Witty said that worry and mild or moderate anxiety ‘can be a normal part of growing up’ but that being in school can often help.

Since the pandemic there has been growing concern about tumbling attendance figures – particularly among secondary school pupils – where persistent absenteeism has become ‘endemic’ in some settings, say education experts.

Figures for the 2022/23 autumn term suggest almost 25% of pupils were persisently absent – meaning that they missed 10% or more of school – compared to just 10.9% in 2019.

In his letter, also signed by other medical professionals, Chris Witty says his team recognise that coronavirus may also have left some parents feeling ‘less confident’ in deciding whether their child can come to school. But – that as a general rule – children with a mild illness were considered well enough to come into class.

In asking schools to share with families the NHS’s guidance, Chris Witty explained that general cold symptoms including a minor cough, runny nose or sore throat, shouldn’t stop children attending but that pupils should not be sent in with a temperature of 38C or above.

He added: “There is wide agreement among health professionals and educational professionals that school attendance is vital to the life chances of children and young people.

“Being in school improves health, wellbeing and socialisation throughout the life course. The greatest benefits come from children and young people attending school regularly.”

Details of the letter were revealed as the man expected to takeover as Ofsted’s chief inspector demanded a review of school absences since Covid.

Speaking to MPs this week, Sir Martyn Oliver suggested September’s heatwave and “some of the issues we are reading in the news” – which was taken to mean the RAAC concrete problems – could further damage attendance just days into the new term.

Giving evidence to a pre-appointment hearing of the Commons education committee, he said: “Right now I desperately need Ofsted to do a thematic dive into attendance – right now.”

In July the government announced plans to expand its child flu immunisation programme to include more secondary school pupils as part of efforts to bolster attendance.

Three million pupils in years 7 to 11 will now be offered the nasal spray, on top of all primary pupils from years reception to 6 and all children who will be aged two or three as of August 31 this year.

Speaking at the time, schools minister, Nick Gibb, said he hoped the change would help keep some teenagers in school over winter.

He added: “Following the disruption caused by the pandemic, it’s important that children are able to attend school as much as possible.

“We know that school attendance levels drop over the winter months due to illness, which is why today’s announcement will not only protect children’s health but also their education.”